Struct FetchOptions 

pub struct FetchOptions {
    pub set_id: [u8; 32],
    pub descriptor_b3: Option<[u8; 32]>,
    pub peers: Vec<String>,
    pub out_dir: PathBuf,
    pub local: Vec<PathBuf>,
    pub want: Want,
    pub max_pieces: Option<usize>,
    pub tls: Option<ClientTls>,
}

Fields

set_id: [u8; 32]

descriptor_b3: Option<[u8; 32]>

When known, the received descriptor must hash to this value; otherwise only the set id (archive hash + geometry) is verified and piece hashes stay provisional until join.

peers: Vec<String>

out_dir: PathBuf

local: Vec<PathBuf>

Volumes (files or directories) already present locally, besides out_dir.

want: Want

max_pieces: Option<usize>

Stop after this many pieces (used to exercise interruption and resume).

tls: Option<ClientTls>

None: plain TCP. Some: every connection is TLS, pinned per peer (see ClientTls).